The CEL with P0328 would come and go the past four weeks. Since the SUV is in the 130k mark, I plan to replace the spark plugs together with the Bank 1 knock sensor. I watched the youTube by CCN on replacing 2GR fe spark plugs and understand that I need to go further by removing the lower intake manifold to access the knock sensor. Will be sourcing the spark plugs, manifold and throttle body gaskets from Bell Lexus. Would getting an aftermarket knock sensor worth doing or buy the OEM from Bell Lexus? This will be my first real DIY after transmission, engine and coolant changes. Am I missing any required materials or routine maintenance works which i could include? Am also hoping that my gas mileage would improve. The 08 RX350 consumes 15.5 mpg on city driving. Would appreciate any inputs. Thanks

 

Be ready for the coil wire clips to break (the locking tab, can replace by depinning, or zip tie, or a dab of rtv), some posts here on replacing those. Have seen very few posts of bad knock sensors so maybe check the wires and connectors to it as well. I would use OE/OEM since its so much work to get there...

Also, while all that top stuff is off, look at your bank 1 VVT oil line and make sure is does not turn to rubber just below the head. Of course you have already checked for rubber oil cooler lines if so equipped (tow package). Toyota also calls these oil lines, but they are different ones.

 

Thanks Mesquite77 for the warning. Will have to play with the front bank to get a feel of loosening those pins. And yes, will get the OEM sensor from Bell Lexus which has the best price among dealers. I Just don't know which among the sensors Rockauto sells is the OEM.

I believe the Bank 1 VVT oil line you are referring is all-metal oil line: 15772-31030. My mechanic had replaced that together with the PS pump around 3 months ago. The other rubber oil cooler had been replaced by the previous owner. Thanks again.

 

Depinning the coil connectors is very easy and quick, I did mine a year ago took only minutes once I figured it out. I forget if I used an X-Acto blade or a pick the videos on YT showed how to do it. Do one wire at a time so you keep the order correct

 

Thanks Leeper. I saw the one in YT using 90 deg pick. Looks easy but not sure for first timer. If not I got the electrical connector plier bought from amazon.
Ordered the following manifold gaskets: 3 pcs 17176-0P021 (orange colored)
1 pc 17177-0P21
1 pc 17178-0P21
And another one for the Throttle Body. Am i missing anything?
Thanks again.

 

parts arrived and tried to feel how to replace spark plug by working on the front Bank 2. All connectors were brittle and easily broke. De-pinned all 3 and replaced with new ones from Amazon. Yes, this method is easier than splicing.
Looks like the previous owner had replaced the coils and spark plugs. The part # Toyota 90919-A2004 is nowhere to be found but instead an inscription RO32303060 is on the side. Do i need to get new OEM for the back ones once I proceed to remove the manifold? It is pricey and is used OEM worth it or just use these aftermarket coils anyway it is not giving any trouble. I am just weighing the labor time accessing the back ones vs the part costs. Would appreciate any input. Thanks

 

After removing the surge air tank, lower manifold has to follow by disengaging the fuel line. How do i depressurize the line and disconnect the line at the blue colored junction? Any help is appreciated.

was able to duplicate depinning connectors as shown in youTube. Thanks Leeper for the tip.

 

glad I could help

 

had to get and add the 1-3/4 inch extension to the spark plug socket plus 3-inch locking extension bar to fit the torque wrench head for 3rd and 5th cylinders. The 1-3/4 inch does not normally come with the 3, 6 and 10 inches set. Luckily, was able to get from HF. Very tight RE space and every mm helps.

 

was able to remove the lower manifold. Haynes manual indicated to unhook the fuel line and drain the coolant which i think is unnecessary for this model. The knock sensor for bank 1 is now accessible.

 

tested the knock sensor and i believe it is a good one since its ohm reading is the same as the new one i ordered from Bell Lexus. How do I check the connector if it were Ok? Physically it looks fine and wirings are tight. However, the area around the gasket was oily and i am thinking it was a gasket issue for which the code p0328 would come and go. Would appreciate if anyone could show how to test the electrical side to avoid going this far again if needed. Thanks in advance.

 

Finally closed the engine and returned the knock sensor to Bell Lexus. To date had ran almost 200 miles with no CEL and smoother run as the throttle body was also cleaned. Happy with the work done although the job was completed in three-week's time vs around 4-5 hours if done by a licensed mechanics. Learned a couple of new tricks specially putting back the bolt in the bracket for the surge air tank. As one could barely turn the bolt holding the head, it was easier to put a socket on it and turn the socket instead. Had to learn it the hard way after dropping the bolt three or four times. Also became familiar with the tools as this was the first job after lube, transmission and coolant replacements. Perseverance did it and with the ups and down of doing it the feeling is priceless.